ATOMIC MASS: the



The Development of the Theory of the AtomTHE INDIVISIBLE ATOMGREEK – DEMOCRITUS (450 BC)Atom was _________________________Theorized the _______________________ of the atom Also, theorized that there were just four 'elements' - _______, _______, _______, and _______.JOHN DALTON (1803)Atom was _______________________All _____________________ are composed of atomsThe same atoms for one element are __________________________ alikeAtoms are neither created nor destroyed in a ________________________.In a chemical reaction, atoms are ____________________________, _________________________, or _______________________________.THE DIVISIBLE ATOMJ. J. THOMASON (1897)discovered the _________________ using the cathode ray tube. determined that the electron was smaller than a __________________ atom. Knew the atom was _____________ and the electron was ___________________, so there must be positive material with a lot more mass. Said the atom was a _______________________________ material throughout which _________________ charged electrons were scattered - Plum Pudding or Chocolate Chip Cookie Model.ERNEST RUTHERFORD (1909)Did a famous gold foil experiment (the _____________ __________________ experiment)Calculated that the atom was mostly ___________________ through which ________________ move. Concluded that the atom has a __________, dense, _________________ charged, _________________-located nucleus surrounded by negatively charged _______________.ERNEST RUTHERFORD (1919)Called the positive particles ____________________.ERNEST RUTHERFORD and JAMES CHADWICK (1932) showed the nucleus also had ______________________The neutron was basically equal in mass to the proton but had _______ ____________________ charge.NEILS BOHR (1914)Concluded that ________________ moved around the nucleus in definite orbits or ___________________________.DALTON REVISITEDAtom was indivisible. _____________All elements are composed of atoms. _____________The same atoms for one element are exactly alike. _____________Atoms are neither created or destroyed in a chemical reaction. _____________In a chemical reaction, atoms are separated, combined, or rearranged. _________THE CURRENT ATOMis ___________________ shaped with a dense, centrally located, positive nucleus containing _____________ and __________________.surrounded by one or more negatively charged ________________ in an electron cloud. Most of the atom’s _______________ consists of fast moving electrons traveling through the _______________________ that surrounds the ________________. Electrons are held within the atom by an ______________________ to the positive nucleus. The nucleus has _____________ neutrons and _______________ protons and _____________ of the mass. Since atoms are electrically neutral, the ______________ of protons must ______________ the number of electrons.ATOMIC STRUCTUREELEMENT: One of the __________ known _____________ substances. Listed on the periodic table.ATOM: ______________________ piece of matter that still retains the properties of that matter. ______________________ in the world is made of atoms.NUCLEUS: _________________ of the atom; _________________ of the mass of the atom; contains _______ particle types; has a _______________________ charge.ELECTRON CLOUD: Surrounds the _____________________; Contains _______ particle type; Has a ____________________ charge.PROTON, p+: All are _____________________, regardless of the element. Location: ________________; Charge ______________________; Relative mass ______________NEUTRON, n: All are _____________________, regardless of the element. Location: ________________; Charge ______________________; Relative mass ______________ELECTRON, e-: Location: ________________; Charge ______________________; Relative mass ______________; Number in an atom: number of electrons = __________________ protons (neutral atom)What makes one element different from another element? ____________________________________IMPORTANT NUMBERSATOMIC NUMBER, Z: equals the number of ________________________________;5619750641350determines the ____________________ of the element; On the periodic table, starts at __________ and goes up in order; It is the “5” in the symbol to the right.ATOMIC MASS: the ____________________ of the masses of the isotopes of an atom; the ______ on the periodic table; IT IS ________ the masses of the protons, neutrons, and electrons added together!MASS NUMBER, A: the number of __________________ and ___________________ (nucleons) added together; take the ______________________ (round!) of the atomic mass to get the mass number; It is the “11” in the symbol to the right; Also can be written after the element’s name: _________________________.HOW DO YOU DETERMINE THE NUMBER OF…..PROTONNEUTRONELECTRONREMEMBER:The atomic number of an element _______________ changes.The number of protons is __________________ the same.The number of ______________________________________________ can change and the element is still the same element.===============================================================PRACTICE:How many protons and electrons are present in a vanadium atom? ________How many protons and electrons are present in a nitrogen atom?________How many protons and electrons are present in an argon atom?________What is the name of the element that has atoms that contain 5 protons? ____________How many protons, neutrons, and electrons are present in zirconium-91?protons _____neutrons _____electrons _____How many protons, neutrons, and electrons are present in cesium-140?protons _____neutrons _____electrons _____What is the atomic number and the mass number for the element with 27 protons and 32 neutrons?Atomic # ______Mass # ______What is the atomic number and mass number for the element with 84 protons and 125 neutrons?Atomic # ______Mass # ______ ................
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